Low air pressure sprinkler system



H. N. R IDER 2,352,996

LOW AIR PRESSURE SPRINKLER SYSTEM Filed March 16, 1942 5 Sheets-Sheet 1 Gttonieg Snnentor' July 4, 1944.

LOW AIR FRESSURE SPRINKLER SYSTEM Filed March 16, 1942 H. N. RIDER 2,352,996

5 Sheets-Sheet 2 I 22 27 I 35 33- 5 3/ 34 I 27 2?; 1 I

3nnentor Hw 44%,

July 4,1944. RIDER 2,352,996

LOW AIR PRESSURE SPRINKLER SYSTEM Filed March 16, 1942 5 Sheets-Sheet 3 IN\7/PI IN TOR. 1 envy/1 lypr F 3 BY ZW I ATTORNEY.

July 4, 1944. I H, N, RgDER 2,352,996

LOW AIR PRESSURE. SPRINKLER SYSTEM Filed March 16, 1942 v 5 Sheets-Sheet 4 Suva/wimp haw/7 M 2 4 July 4, 1944.

HANTP LOW AIR PRESSURE SPRINKLER SYSTEM- Filed March 16, 1942 5 Sheets-Sheet 5 grvucm bov Patented July 4, 1944 LOW AIR PRESSURE SPRINKLER SYSTEM Harry N. Rider, Youngstown, Ohio, assignor to .Automatic Sprinkler Company of America, Youngstown, Ohio, a corporation of Delaware Application March 16, 1942, Serial No. 434,858

, 4 Claims.

This invention relates .to an automatic sprinkler system for the control of fire and particularly toa system fully-automatic in operation and wherein a-slight reduction of low pressure air in the sprinkler system results the sprinkler systems going into operation.

The principal object of this-invention is the provision of :an automatic sprinkler systemwhich will operate @efficiently with an air pressure carried therein substantially lower .than pressures heretofore generally carried 'in' dry pipesystems. l

A further object of the invention is the provision of a low air pressure sprinkler system employingin combination a dry pipe valve which responds rapidly to decreases in'air pressures; eliminating the necessity-of employing quick Y acting devices such as accelerators or exhaustors, and a water "powered airpump which serve to maintain suitable air pressure in the piping -of the sprinkler system. i

A further object *of the invention is the provision of a sprinkler system incorporating the dry pipe valve which will make it possible to maintain a relatively low'air pressure :in the piping 'of the sprinkler system which will result in water reaching the sprinklers immediately valve is automatically primed and" wherein 'condensate and liquid residue are automatically drained;

A further object of the invention is the provision of "a sprinkler'system "having adry pipe valve therein "incorporating electric switches which are'actuate'd in such a manner that an alarmis givenin advanceof the opening of the dry pipe valve and the subsequent delivery of water by the sprinkler system.

With the foregoing-and" other objects in view which-will appear as the description proceeds, the invention resides in the combination andarrangementof partsand in'th'e details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the-invention herein disclosed,

can be made withinthe scopeof what is claimed without departing from the spirit of the inven- 7 tion.

' away and illustrating a complete system formed Theinvention is illustrated in the accompanying drawings, wherein: V

Figure 1 is an elevational view-of a low-air pressure sprinkler system-with parts broken in accordance with the present invention.

Figure'2 is a side elevational view of the low air pressure sprinkler system shown in Figure 1.

Figure 3 is a cross sectional elevation of the dry pipe valve and associated operating'means which forms a part 0f the-low air-pressure sprinkler system. I

Figure 4 is a cross sectional side elevation taken approximately on lines 4-4. ofcFigure 3 illustrating the dry pipe valve-actuating means,

the dry pipe valve body not being. shown in Figure 4.

Figure-5 is a cross sectional view takenon al proximately lines -5--5 of Figure 2 illustratin the details ofconstructionof the water powered air pump which forms a-portion of the sprinkler system. I

Figure 6 is a cross sectionalelevation of an alarm valve.

Figure 7 is across sectional side elevation of i a velocity ball check-valve apart of the lowair pressure sprinklersystem shown in Figure -1:

By referring to the drawings'and'Figuresl and 2 in particular, it -will 'be observed that the low air pressure sprinkler system comprises amain fluid supply pipe I'll for supplying fire extinguishing fluid under pressure provided with-a manual gate valve H and with an automatically operating dry pipe valve 12. The fluid supply is conducted from the-dry pipe valve through a riser l3having suitablebranch pipes Hlwhichin turn are equipped with sprinklers Ill. The branch pipes I4 lead to the different fire zones of the structure in which the low air pressure sprinkler system' is installed.

The gate valve ll is controlled by means ofa hand wheel l6 and'valve'operating-shaft placed within ayoke ll of the gate valve I l. Thegate valve I is normally open so that the fluid supply entering thesystem through the pipe 10 is actually controlled by thedry pipe valve I2 which dry pipe valve 12 is shown in detail in Figure 3 of the drawings. The dry pipevalve includes a latched clapper in its construction and at such times-as the sprinklensystem is ready for operation, but not in actual operation delivering drawings, the air pumps mechanismflenclosing housing is indicated by the numeral I9 and a water leg included in the air pumps construetion and essential thereto is indicated by the numeral 20. above the body member I8 of the water powered pipes 21 and 28 into the dry pipe valve body I2 and upwardly into the system through the riser I 3 and the other associated parts. In order that an alarm may be given when the system goes into operation as in extinguishing a fire, a relatively small alarm valve 33 communicates with the pipe 28 adjacent the fitting 29 which communicates with the interior of the dry pipe valve I2. When the clapper in the dry pipe valve I2 opens, Water under pressure enters the same and flows upwardly through the riser I3 and outwardly through the pipe 28 and forces open the A secondary water leg 2I extends air pump and the upper most end thereof isproe vided with an L 22 which forms an overflow pas-- pressure and its mode'of operation in supplying the said air will'be developed herein. 'It willbe seen that the'water powered air pump I8 is" supplied with fluid through a pipe 25 which'communicates 'with the main fluid supply through the gate valve II, communicating with the gate valve lfbelowthe gate therein, and is provided with a sediment trap '26 to insure the delivery of clean fluid to the air pump l8. ringto Figure 1, it will be seen that a pipe 2! communicateswith jthe water poweredair pump I8 and extends upwardly therefrom terminating in a pressure gauge. Two'branch' pipes com: municate with the pipeZ'I the lowermost one of which is indicated by the numeral 2-8 also com municates with the interior of'the dry pipe valve I2 above the clapper therein through a fitt ng 25. A velocity ball checkvalveis positioned in the pipe 28 and is indicated by the numeral This velocity ball check valve 3!! permits the free flow of air from the body l8 of the air pump into the body l2 of the dry pipe valve, and permits condensate and residue liquid in the system above the fitting 29 to drain therethrough into the air pump I8; By referring' to Figure 2 01 the'draw ings, a cross sectional side elevation of the velocity ball check valve 30 may be seen to comprise a pair of valve bodies 30 and 30A threadably engaging one another and containing a'h-all 303 which is adapted to normally remain in the position shown and move res onsive to abnorma pressure from the left hand side of the. valve seat 300 formed in the body 30. The valve seat 300 is provided with a relati ely small notch 30D" which causes the velocity ball check valve to open faster when abnormal pressure a ainst the same is released. The seat portion 300 of the valve is positioned opposite the ressu e inlet which in this disclosure comprises the fitting 2! communicating with the dr pipe valve !.2 above the clapper thereof. The uppermost of the. two p nes communicatin with the upwardlv extending nine 21 is indicated by the numeral 3| and al o communicates with the actuating ortion f the dry pipe valve indicated by the numeral 32. Thus air under pressure established by the air ump" in the body portion I8 thereof flows through the Still refer alarm valve 33 from whence it travels by means of pipes 34 and 35 to a pressure switch 36 and if desired through a continuation of the pipe 35 indicated in the drawings by the numeral 35A to a water motor alarm. The velocity ball check valve 30 prevents water from flowing through the pipe 28 into the pipe 21 and the air pump body l8 as the velocity of the water entering the velocity ball check valve 30 actuates the same. The pressure switch 36 may be any commercially available pressure operated switch which may obviously actuate any desirabl alarm connected therewith. It will also be seen that'connecting with the fitting 29 on the dry pipe valve I2 and extending upwardly therefrom there is a pipe 31 providedwitha sprinkler 31A which when the system is' in operationwill serve to protect the valve and pump assemblies from fire.

It'will beseen that a dry pipe system has been "provided wherein water from the supply source is prevented from entering the system by means of the dry pipe valve I2 and that the system itself is filled with air under low pressure which is supplied and maintained by the water powparticular it will 'be seen that the dry pipe valve comprises a body I2 in which a water inlet is indicated at 38. In order that the water inlet 38 may be effectively separated from the remainder of the valve body, an annular shoulder 39 provided with a seat ring 40 adapted to receive a clapper 4I serves to effectively control the admission of water into the valve body from the waterinlet 38. A suitable rubber facing 42 is affixed to the clapper M by means of a clamping ring 43 which in turn is affixed to the clapper 4| by means of a plurality of cap screws.

The clapper 4I is formed with a pair of hin e arms 44 adapted to pivot about a hinge pin 45 so as to effectively hinge the clapper in relation thereto. The'hinge pin 45 is carried on suitable bushings positioned in the valve body I2. In or" der that the clapper 4| will remain in closed position on the'water inlet 38 and thus prevent the passage ofwater through the valve. a latch mechanism is positioned within the valve bodv and adjacent to a shoulder 46 formed on the clapper 4!. The latch mechanism comprises a latch 41 pivoted to the valvebody by means of a latch hinge pin 48 so that horizontal movement imparted to the lower end of the latch 41 results in moving it from its seat on the shoulder 4B of the clapper 4| thus effectively releesin-g the clapper 4| and permitting Water in the water inlet 38 to raise the clapper 4| and flow through .the valve. Still referring. to the; latch mechanism it willwbeseen that the latch 41 has an z anti-reseatingt portion -49 pivoted thereto and adapted togprevent the-clapper l-i from -reseatlng. .Inlorder that the anti-reseating :latch 149 remain ineffective operating positicn, a latch spring .510 .is utilized which serves to position the anti-reseat-ing latch portion 49 inoperative relation tO'thecIapper-M at -all;-times.

.In order that movement may be imparted :to this latch 41 so as to result in the opening of the clapper, a latch link'5l is pivoted at itsiinnermost end to the latch '41 by-meansof :a link'pin 52. flhislatch link 5i passes centrally through and 'iseafiixed to a circular latch linkdiaphragm 53 which is positioned in l-a water ltightt manner acrosslanopening 54 in .the-sideof the valve body IZ and thus permits the transmittal .of movement through the latch link 5-l while effectively closing the opening '54 in the valve body 12. The latch link '5! passes through an opening in the diaphragm 53 and-is :aifixed therein in-a water tight manner 'by means of :a nut 55 threaded thereon so as tooppose an annular shoulder-5ii formed on'the latch link '51. Aporti'on of :the latch link extends outwardly from the annular shoulder 56 and comprises'in effect-a .T headed connection section adapted lto'receive in amovab'le manner a latch arm 5'! which is part of a -valve-actuating mechanism which comprises a vertically :positioned actuating mechanism box 58 bolted by means-of bolts 59 to the valve body 12 :at apoint thereon adjacent the opening 54 thereof so that its mechanism effectively imparts movement to the latch link 5|.

The latch arm 5-! is pivoted by means of a hinge pin 60 to the box Etand is 'adapt-eduto impart movement to the latch link 5|. In order that the latch arm ,5! may receive movement suit able for actuating the latch link 5| and, in turn, the latch 47, an end 61 thereof is pivoted bymeans of a pin :62 to the lowermost end of avertically positioned guide rod 63.

By referring to'Figure 4 of the drawings'it'will hejseen' that theup permostrend o'fithis guide rod 63'is-slideably positioned-within a sleeve 64 which is in turn carried upon a portion 55 of a release frame 65. -A pin is positioned through the uide rod63 so as to limit the upward movement thereof which might otherwise :interfere with the action of the releasing mechanism. A weight'ii'l having a centrally positioned opening 58' therein is positioned on the rod :63 so as to be slideable vertically thereof. In order that the weight 61 may be maintained in elevated position as shown in thedrawings, a barbed shaft 59 is afiixed thereto in a flexible manner by means of a retaining plate anda coil spring H. The barbed shaft 69 is retained in position by means of a barb latch 12 pivoted to a bracket on the portion 65 of the release frame-66 by means of a pin E3. The opposite end of the barb latch 12 tapers to a point adapted to be retained beneath ailedae M formed on a disk affixed to a diaphra m which is in turn positioned on and over an opening formed by the release frame 66. A coil spring 6 is positioned between the inner side of the diaphragm l5 and an adjacent section 3'! of the release frame 66 so that the coil spring 15 tends to move the diaphragm 15 outwardly so as to release the pointed end of the barb latch from beneath the ledge 14 of the disk positioned thereon. By referring to Figure 3 it will be seen that the section l1 referred to is tubular in shape and threadably positioned within a threaded opening in the porill) tiondi 5pfithelielease1trame :66. In order that an aiirzpressuremhamber mayibelformed adjacent the diaphragm 153a diaphragmzcap 'l8.is bolted to the releaserframe :66 and the box :58 adjacent the .dia phragm 15. A gasket i9 is positioned between the diaphragm cap and :the releaseirame 66 to insurera tight joint and the diaphragm cap 18 is provided with the threaded opening 32 adapted to receive and communicate with the piping 1.3I and 21 through which communication is establishedzwith 'the' body A8 10f the. air pump (and with the --valve :body I2 "so that thepressure chamber formed adjacent the diaphragm '75 will receive and retain airiunder pressure equal to'that in the valve body 1 Zria-nd sprinklerv system.

".In' operation the 'airrunder vpressure in the pip ing :of the sprinkler "system will be released upon the opening tof .any given sprinkler thus resulting in arrapidt-decrease of air pressure within the diaphragm cap 1*8. This decrease in air pressure resultsiin the ncilspring TB moV-ing the'diaphragm 15 outwardly'into the area-within the diaphragm cap and thus release the barb latch 12 from bemonth the ledge 1410f .thed-iaph'ragm; When this occurs the barbed shaft 69 and'theweight .61' drops downwardly .along the guide rod .63 and the Weight :61 strikes the end-5130f the .arm '5] thus effectively "moving the same. This action moves the latch link 5! outwardly together with the 'latch'flwvhich results inthe unlatching of the clapper.

Inorder thatthe low'pressure dry pipe valve maybe operated m'anua'fl'ly'if desired, as for eX-' ample, at such itimes z'asa fire 'is' observed in its early stages, mechanism has been "incorporated to permit the'manual release of the weight 61 which will effectively cause the dry pipe valve to be .unlatched and permit theisprinkler system to be :filledwi'th water. By referring to Figure 4 wherein this mechanism is illustratedmore clear-' 1y, it'wi'll be seen that :a manual release arm is pivoted to a'bracket formed on 'a'portion 55 of therelease 'frame' 66 by means of a pin 8! and.

that its upper end forms an operating lever' 82 l shaped to 'fi't :under an edge of the barh on the barbedshaft $9 in opposite relation to the barb latch 'l'z. A tension spring 83 positioned about thezpin B-l serves to hold the manual release arm and operating lever 82 in position. By referring l to the lower end of thearm 80 it :will be seen that a rod 8 is attached thereto by suitable pivotmeans and carries on its outermost end apush buttoni85 which is slideably positioned "within an opening in 'a cover portion 86 o'fthe -actuating mechanism box :58. It will lbeseen that by pushing the push button 85 inwardly-the arm 8!) turns or pivots upon the :pin 8! and effectively releases the operating lever 182 from beneath the jbarbed' shaft 39 thuse'ffectively permitting the weight to drop and actuate the valve.

Still referring to Eigure i it-will be seen that electric switches are incorporated with the valve releasing vmechanism and comprises a pair of mercury switches :81! positioned in suitable clamps on :a tiltable base 88 which is pivoted at its outermost end to aterminal block 89. seen that as long'as :the weight' fii is in its up- Dermost position as "shown in the drawin s. the base 88 carrying the mercury switches 8'! will remain "tilted and efiec'tively keep the switches open-and'thatwhen the weight "61 drops the base 88 will follow that movement a relatively short distance thus effectively closing "the "circuit I through the mercury switches which tilt into closed position. It will be obvious that any other It will be" type of electric switch may be utilized so as to be operative at such times as the weight 8'! is released by the valve operating mechanism. Thus an electrical alarm may be given prior to the actual opening of the dry pipe valve I2 :which is of considerable value'in the event that the water supply to the dry pipe valve has been interrupted.

Having thus described the specific dry pipe valve and actuating mechanism used as a component part of the low air pressure sprinkler system, the following concerns the water powered air pump I8 and comprises a specific description of the operating structure thereof.

By referring to Figure 5 of thedrawings, it will be seen that the air pump comprises a body member I8 on one side of which there is positioned a mechanism enclosing-housing I9 which in turn is secured to the body member I8 by means of bolts 98 functioning through openings in the flange 9| formed on the housing I9; The housing I9 is positioned over a large opening in the body member I8. Positioned in this large opening there is a pressure responsive valve operative mechanism.

By referring again to Figure 1 ofthe drawings, it will be observed that the bottom of the body member I8 is provided with an opening in which is positioned the water leg 28 which is provided at its lower extremity with a cap 93 which in turn is provided with a plugged opening 94. Positioned vertically through the body member I8 and extending downwardly within'the water leg 28 there is a secondary tubular water leg 2| which terminates short of the bottom of the water leg 28 and emerges through an opening in the top of the body member I8 and is provided with an L 22 which forms the overflow passage for water rising upwardly through the secondary water leg 2|.

In order that water and air may be introduced into the body member I8 in order that the air pump action may take place, a jet pump chamber 95 is afilxed by means of bolts 96 to one side of the body member I8 as may be seen in Figure 2, and by referring to Figure 5 and to the right hand portion thereof wherein a cross sectional detailed View of the jet pump is shown it will be seen that water entering by way of an orifice 91 is directed, at such times as a water control valve 98 is open, through a jet 99 and into a Venturi jet pump I88 by which action it causes a quantity of air to be delivered therewith into the body member I8 of the pump by way of an upwardly extending communication channel IOI which in turn forms a part of the jet pump housing 95A and is bolted to the body member I8 by bolts 96. Air is introduced into the Venturi jet pump through an orifice I82 in the bottom of the jet pump chamber 95. When the valve 98 is open; and water enters from the pipe 25, the resultant action of the water passing into the Venturi jet pump will be the introduction of a substantial quantity of air into the body member I8 along with the water. The water introduced will flow downwardly through the water leg 28 which communicates with the bottom portion of the body member I8 and subsequently rise within the secondary water leg 2| to the uppermost end thereof which is substantially above the body member I8 from which it will be discharged.

In order that the air introduced into the body member I8 may beretained so that a workable air pressure may be built up in the piping of the sprinkler system associated therewith by way of the pipes 21 and 28, a'diaphragm'l83 which carries a centrally positioned piston like structure I84 is positioned in the large opening between the body member I8 and the housing I9 the outer extremity of the diaphragm I83 being securely positioned between the flange of the body member I8 and the flange 9I of the housing I9. Thus air introduced into the body member I8 is restricted thereto by the flexible diaphragm I83 and its piston like structure I04 which forms a flexible water and air tight seal.

It will thus be observed that when, due to the continuous operation of the Venturi jet pump, a satisfactory air pressure has been built up'within the body member I8 of the pump and the associated piping of the sprinkler system, the normal tendency of the diaphragm I83 will be to move outwardly into the adjacent housing and in order that this movement may be suitably utilized to control the introduction of water into the Venturi jet pump, means has been associated with the diaphragm I83 and the Water control valve 98 for either opening or closing the valve 98 in accordance with the position of the diaphragm I83 and its piston like structure I84 which in turn is adjustably opposed'by a coil spring I85 with respect to a tubular adjustment member I05 which is threadably positioned in a threaded opening in the housing I9. The tubular adjustment member I86, threadably positioned in the opening in the housing I9, permits the tension on the spring I85 to be varied so that any desirable air pressure may be maintained within the body member I 8. In order that the movement of the piston like structure I84 carried on the diaphragm I83 will result in movement of the water control valve 98, a rod I0! is afiixed in an opening formed in a centrally located boss I88 on the piston like structure I84, and extends outwardly therefrom and terminates in a pivot structure I89 connected to an end of a secondary rod II8 which engages a part of the water control valve 98 by reason of an end thereof functioning within a suitable opening in the water control valve 98. The rod H8 is pivoted to an adjacent portion of the jet pump chamber by a pivot III. Immediately surrounding the rod H8 and pivot I II and forming a flexible water tight seal there is a diaphragm gland I I2 which is positioned between a bracket I I3 located within the housing I9 and a portion of the jet pump chamber 95 so that the rod II8 passes therethrough in a movable manner.

In order that the action of the water control valve 98 may be controlled and adjusted with respect to the air pressure built up within the body member I8 by the pump action, spring tensioned adjustment means have been provided to limit the movement of the rod I01, which is moved by the diaphragm I83 and its piston like structure I84, and comprises a pair of roller carrying arms II4 pivoted at H5 to a bracket I I8 which is in turn affixed to the housing I9. The rollers carried on the roller arms II4 engage the rod I91 and, as the rod I8! is provided with an irr gular surface, tension brought to bear between the opposite ends of the roller arms II4 by means of an adjustably mounted spring I I1 effectively cone trols the movement of the rod I81 until a desirable pressure against the diaphragm I 83 has been established. The spring II! is adjusted with respect to the roller arms I I4 by means of an ad- J'ustment screw II8.

It will thus be observed that at such times as the air within the body member I8 reaches a aseagoe'c predetermined pressure the diaphragm I03 and the piston like structure I04 will sufiiciently'c'ompress the spring I05; to enable the rods I01 and H0 to close the water control valve 93, and that when such action has taken place the water which has been overflowing through th L 22 on the upper end of the secondary water leg 2| will, as the air pressure'within the body member I8 of the pump diminishes, drop within the' secondary water leg 2| in direct relation thereto and thus serve to maintain the air pressure within the body member as the column of water rises in the water leg 20. This action continues until the water within the secondary water leg 2| has dropped to a level where it can no longer effectively move the column of water upwardly within the water leg 2i. From this point on diminishing air pressure within the body member l8, as may be occasioned by leakage in the sprinkler system, results in the spring 35 moving the diaphragm [t3 and the piston like structure I34 into the body member I8. and thus. effectively opening the water control valve 98 which oompletes the cycle of operation. It will thus be seen that the action ofthis water powered air pump is entirely automatic and that due to the dual water leg construction the air pressure developed by the pump is maintained satisfactorily during the intervals betweenthe actual pumping periods.

It will thus be seen that the sprinkler system and component parts .have been designed to achieve certain advantages not heretofore known to the art, one of the principai'ones" of which is its ability to operate. in the event of fire with remarkably low air pressure in the piping of the sprinkler system and to open the dry pipe valve upon a reduction of this low air pressure by only a fraction of a pound. This permits the relatively simple and responsive air pump to be used in the system which is obviously an advantage when compared with the more expensive electric air compressors heretofore necessary to maintain relatively high pressures in the piping of the sprinkler system. Another advantage resulting through the use of extremely low air pressure in the piping of the sprinkler system is in that the air when put into the system will not be of high temperature and, therefore, the condensation in the piping will be much less than has heretofore been the case. This will tend to eliminate broken pipes caused by the freezing of condensate in cold weather. Another advantage resulting from the low air pressure carried in the piping of the sprinkler system is that the fanning of the fire with compressed air escaping from sprinklers is eliminated as the relatively small quantity of air in the piping of the system escapes rapidly and permits the water to reach the sprinklers more quickly. A low air pressure sprinkler system formed in accordance with this invention may be tested at frequent intervals, and particularly the dry pipe valve thereof without filling the piping of the sprinkler system with water, as the operating mechanisms except for one latch are external parts and further, the priming of the valve of the system occurs when the water supply in the Water supply pipe It comes in contact with the under side of theclapper ii and there are, therefore, no external pipe connections for priming purposes It will also be seen that the sprinkler system may be reset for use after operation in a relatively short time as there is no need of building high air pressure in the piping of the sprinkler system therefrom through the drain pipe 24 which is at all other times normallycl'osed at its connection with the drytpipe valve. It will thus. beseen that an efficient dry pipe sprinkler system operating upon a fractionaldrop in the relatively low air pressure carried in the piping of the system has been designed. The system is completely automatic in operation and is not. dependent upon electric circuits for'operation, as the water supply source maintains. the low air pressure in the system," loss ofwhich causes the system to go into operation in controlling afire upon the opening of any one or more. of the sprinklers forming apart thereof, It will alSO'bB seen that the low air pressuresp-rinkler system. has. an inherent'advantage due to the combination .of its component parts which advantage comprises the ability'of the sys'te'mto self prime the clapper 4! or" the valve l2 andprovide for the drainage from the system of condensate or residue liquid after use, which will drain through the. velocity ball check valve 38 in a, dribble actionIinto the air pump l8 and outwardly therefromv through the secondarywater leg El" and the I. 22'. due to the air pumps action. [The system is thusautomatically primed at all times and need not be manually serviced at frequent intervals as is the case with other systems heretofore known in the art. This action is mad possible by. the'combination of the specific air pump 13'. with the other portions of the sprinkler. system.

By referring to Figure 6, the alarmivalve 33 may be seen to comprise-avalveseat I ZlI-adapted to be normally closed by. avertically movable valve disk 12! which inturn is part of. a valve assembly including "a L downwardly depending guide E22 which guide has a plurality of Vertically positioned openings therein and an upwardly extending rod I23 which telescopically engages a cylinder I24 in the uppermost portion of the alarm valve 33. A coil spring I35 is positioned between a portion of the alarm valve body 33 and the valve assembly disk I2I. The tension on the coil spring I35 is adjustable so that the alarm valve may be set to permit the flow of fluid therethrough only at such times as the sprinkler system on which it is installed goes into action delivering fire extinguishing fluid. Fluid enters the alarm valve through an inlet I36 and leaves it through an outlet I31.

Having thus described my invention, what I claim is:

1. In afire extinguishing system having distributing pipes normally containing air at 1 pounds pressure and an automatic valve in connection therewith controlling the entrance of fluid thereinto, the said automatic valve responsive to a reduction in the said air pressure in the distributing pipes, means for. supplying air to said system and draining off excess fluid above the priming level of the automatic valve when said automatic valve is closed, said means comprising a Ventur-i jet type air pump in communication with said automatic valve for maintainafter the fluid in the system has been drained ing the low air pressure in the said distributing pipes, the said air pump enclosing an air head and including a water column and overflow therefor forming a liquid seal, a velocity ball from the automatic valve when the system goes into operation in extinguishing a fire.

2. In a fire extinguishing system having distributing pipes normally containing air at 1 /2 pounds pressure and an automatic valve in connection therewith controlling the entrance of fluid thereinto, the said automatic valve responsive to a reduction in the said air pressure in the distributing pipes, means for supplying air to said system and draining off excess fluid above the priming level of the automatic valve when said automatic valve is closed and means for initiating an alarm when the said draining means becomes inoperative and when the system goes into operation in extinguishing a fire, said means I comprising an alarm valve in direct communication with the distribution system side of the said automatic valve and an alarm in communication with said alarm valve, the said alarm valve adapted to open when subjected to a pressure slightly higher than that normally existing in the system.

3. In a fire extinguishing system having distributing pipes normally containing air at 1 pounds pressure, closed sprinklers on said disstant air head and a water column and overflow therefor forming a liquid seal therefor, means for closing off communication therebetween, said means responsive to the entrance of fluid into the said distributing pipes as upon the opening of the said automatic valve.

4. In the fire extinguishing system having distributing pipes normally containing air at 1 pounds pressure, closed sprinklers on said distributing pipes, an automatic valve in connection with the said distributing pipes for controlling the entrance of .fluid thereinto, the said automatic valve adapted to be actuated by a reduction in the said air pressure in the distributing pipes, means for supplying air to the said system and draining ofi excess fluid above the priming level of the automatic valve when the automatic valve is closed, said means comprising a fluid operated jet type air pump in communication with the distribution system side of the automatic valve and including a constant air head and a water column and overflow therefor forming a liquid seal, a velocity ball check valve interposed bee tween said air pump and the said automatic valve for shutting 01f communciation therebetween when the system goes into operation in extinguishing a fire, means for'initiating an alarm when the said draining means becomes inoperatable, said means comprising an alarm valve in direct communication with the distribution system side of the automatic valve, the said alarm valve adapted to open when subjected to a pressure slightly higher than that normally existing in the said system.

HARRY N. RIDER. 

